How can the warmer months affect renewable energy?

According to the World Economic Forum, our entire energy system could be powered by renewable energy by 2050. The five key types of renewable energy – wind, biomass, solar, hydro, and geothermal – are uniquely affected by changes in temperature. As Covid-19 changes the way we work and impacts the global demand for energy, we must consider how the warmer months will affect renewable energy and the possibility of a greener future.

While tropical temperatures remain the same throughout the seasons, winter months bring in cooler air that collides with the warm air to create jet streams. Since there is less of a contrast between regions in warmer months, wind speeds tend to drop and both offshore and onshore wind production slows.

As different regions around the world go through the seasons the global wind speeds should remain the same but researchers are observing changing wind patterns. A recent study by Nature Climate Change shows that average wind powers have increased steadily over the last 10 years and this has increased the potential power production of wind turbines by 17%. The report explains that this natural cyclical pattern has the potential to boost our worldwide power production by up to 37% by 2024 and this will likely exaggerate the renewable skills gap.

With its vast expanses of farmland and temperate climate, Asia celebrates the largest contribution to the global supply of biomass, totalling 38%. Bioenergy crops have an optimal temperature at which their yield reaches a maximum output and, just as with solar panels, as the temperature deviates from this threshold the yield begins to drop. In warmer months, some regions become inhospitable both because of rising temperature and the change in precipitation.

Though solar relies on the sun’s energy to generate power, solar panels have optimal conditions at which the process is most efficient. Most PV panels are tested at 250C, making this the prime temperature for photovoltaic cells to absorb the sunlight. During warmer months, and cooler too, the process can become incrementally less efficient as the temperature creeps away from this mark.

Though this is somewhat offset by reduced cloud density in low to medium-latitude regions, warmer months can pose a problem for today’s solar panels and this presents a challenge for the industry to engineer renewable energy technologies that can cope with more extreme weather conditions.

Hydropower accounts for 50% of the world’s renewable energy generation capacity and therefore outranks any other source. This makes hydropower an essential renewable energy source and has led many experts to question how changes in the temperate affect its production, but the answer is not simple. Since there is generally less precipitation in the summer months, rainfall tends to lessen and this reduces the amount of water moving through rivers and dams, shrinking the amount of hydropower produced. However, the warmer weather melts snow in the mountains and this increases the river flow and consequently the generation of hydropower.

With much of the attention focused on wind and solar energy, geothermal tends to take a backseat on the renewable energy scene, despite the potential it has shown over the years. Since 2000, geothermal electricity production has increased by 77% and the International Energy Association is expecting this growth to continue exponentially. So how do hotter temperatures affect the production of geothermal energy?

Geothermal power stations harvest geothermal energy at around 2km below the Earth’s surface where conditions remain constant and unaffected by weather conditions. Meanwhile, geothermal heat pumps harness the Earth’s natural heat at a depth of around two metres, or just below the frost line. While the temperature is much cooler here, it remains unchanged by the air temperature. Therefore, geothermal is an ideal renewable source to produce a consistent level of energy throughout both the warmer and cooler months.